Method for preparing cathode active material of lithium battery

Abstract

A method for preparing a spinel type lithium manganese oxide cathode active material, includes providing a number of manganese dioxide hollow spheres and a lithium source powder, mixing the manganese dioxide hollow spheres and the lithium source powder in a liquid medium to achieve a mixture, drying the mixture to remove the liquid medium to achieve a precursor, and sintering the precursor at a sintering temperature of about 600° C. to about 800° C. for about 3 hours to about 10 hours, to achieve a number of spinel type lithium manganese oxide hollow spheres.

What is claimed is: 
     
       1. A method for preparing a lithium manganese oxide cathode active material, the method comprising:
 providing a plurality of first hollow spheres made of manganese dioxide and a lithium source powder; 
 mixing the plurality of first hollow spheres and the lithium source powder in a liquid medium to achieve a mixture, wherein the plurality of the first hollow spheres and the lithium source powder are both in solid state in the mixture, and a ratio of a total volume of the lithium source powder and the plurality of first hollow spheres to a volume of the liquid medium is from about 1:1 to about 1:5 in the mixture; 
 drying the mixture to remove the liquid medium, thereby achieving a precursor; and 
 sintering the precursor at a sintering temperature of about 600° C. to about 800° C. for about 3 hours to about 10 hours, to achieve a plurality of second hollow spheres made of lithium manganese oxide. 
 
     
     
       2. The method of  claim 1 , wherein the liquid medium is ethanol, a material of the lithium source powder is selected from the group consisting of lithium hydroxide, lithium carbonate, and a combination thereof. 
     
     
       3. The method of  claim 1 , wherein the plurality of first hollow spheres are prepared by following steps:
 providing an amount of manganese carbonate powder; 
 dispersing the amount of manganese carbonate powder into water to form a manganese carbonate water solution; 
 introducing a potassium permanganate solution into the manganese carbonate water solution while stirring the manganese carbonate water solution to form a reaction product; and 
 adding a dilute acid into the reaction product. 
 
     
     
       4. The method of  claim 3 , wherein the manganese carbonate powder is a plurality of manganese carbonate solid spheres. 
     
     
       5. The method of  claim 4 , wherein a molar ratio of the plurality of manganese carbonate solid spheres to the potassium permanganate is from about 1:1 to about 10:1. 
     
     
       6. The method of  claim 3 , wherein the dilute acid is selected from the group consisting of dilute sulfuric acid, dilute hydrochloric acid, dilute nitric acid, and combinations thereof. 
     
     
       7. A method for preparing a lithium manganese oxide cathode active material, the method comprising:
 providing a plurality of first hollow spheres made of manganese dioxide and a lithium carbonate; 
 mixing the plurality of first hollow spheres and the lithium carbonate in a ethanol in room temperature to achieve a mixture, wherein the plurality of the first hollow spheres and the lithium carbonate are both in solid state in the mixture, and a ratio of a total volume of the lithium carbonate and the plurality of first hollow spheres to a volume of the liquid medium is from about 1:1 to about 1:5 in the mixture; 
 drying the mixture to remove the liquid medium, thereby achieving a precursor; and 
 sintering the precursor at a sintering temperature of about 600° C. to about 800° C. for about 3 hours to about 10 hours, to achieve a plurality of second hollow spheres made of lithium manganese oxide. 
 
     
     
       8. The method of  claim 7 , wherein the plurality of first hollow spheres are prepared by following steps:
 providing an amount of manganese carbonate powder; 
 dispersing the amount of manganese carbonate powder into water to form a manganese carbonate water solution; 
 introducing a potassium permanganate solution into the manganese carbonate water solution while stirring the manganese carbonate water solution to form a reaction product; and 
 adding a dilute acid into the reaction product. 
 
     
     
       9. The method of  claim 8 , wherein the manganese carbonate powder is a plurality of manganese carbonate solid spheres. 
     
     
       10. The method of  claim 9 , wherein a molar ratio of the plurality of manganese carbonate solid spheres to the potassium permanganate is from about 1:1 to about 10:1. 
     
     
       11. The method of  claim 8 , wherein the dilute acid is selected from the group consisting of dilute sulfuric acid, dilute hydrochloric acid, dilute nitric acid, and combinations thereof.